Review of existing design methods for geosynthetic-reinforced pile-supported embankments

Embankment construction over soft foundation soils is a challenging task for geotechnical engineers due to the undesirable characteristics of soft soils, such as excessive settlements and low bearing capacity. Among the various ground-improvement methods available for overcoming these undesirable characteristics, geosynthetic-reinforced pile-supported (GRPS) embankments are considered to be a reliable solution suitable for time-bound construction projects and difficult ground conditions. Various researchers have introduced methods to design GRPS embankments based on different load transfer mechanisms. However, among design engineers, there is uncertainty regarding the applicability of these design methods. This paper investigates the load transfer mechanism of GRPS embankments using two-dimensional and three-dimensional finite element analyses, and currently available design methods are compared with the results of the finite element modelling. A comparison of the design methods was carried out using the stress reduction ratio, the geosynthetic tension and pile efficacy, considering different pile diameters and spacing, and embankment heights, which govern the currently available design methods. Based on these model results, the inconsistencies in the currently available design methods are identified and discussed in detail.